Why Biosand Filters?
Biosand filters are an adaptation of slow sand filters, which have been used for hundreds of years in the treatment of community drinking water. Biosand filters can be used with various water sources and they do not require electricity. Due to their relatively compact size and affordability, biosand filters are a reliable, sustainable option for providing households with safe drinking water.
Effective
Biosand filters are about three feet tall and contain several layers of sand and gravel within a plastic or concrete container. As water filters through each of these layers, pathogens and suspended soils are removed from the water, making it safe for human consumption. Biosand filters remove up to 100% of worms and worm eggs, 99.8% of protozoa, 99% of bacteria, and 95% of viruses from unsanitary drinking water. Just one hour of filter use yields up to 5 gallons of water, ensuring communities receive large quantities of drinking water that is free from water-borne illnesses.
Sustainable
Biosand filters provide a sustainable source for clean drinking water. When cared for properly, one biosand filter can provide safe drinking water for up to 10 people for 25 to 30 years. With formal training offered through The Maji Movement, local community members learn to build, install, and maintain water filters throughout their villages. By partnering with individuals in Tanzania, The Maji Movement provides job opportunities, educates locals about waterborne illnesses, and simultaneously builds community empowerment.
How Biosand Filters Work
Biosand filters work by pouring contaminated water from local water sources into the top of the filter. As the water passes through the layers of sand and gravel, pathogens are removed from the contaminated water through the biological and physical processes of predation, trapping, adsorption, and natural death. The result of these processes is filtered water that is safe for drinking.
